Lubricating composition



Patented July 6, 1943 UNITED STATES PATENT OFFICE"LUBRICATISZiZZLIPOSITION A Q A Irvin W. Humphrey, Wilmington, Del.,assignor to Hercules Powder Company, Wilmington, Del., a corporation ofDelaware No Drawing. Application Februa -y 28,1941, Serial No. 381,133

16 Claims.

This invention relates to greases and high viscosity oils. Moreparticularly, it relates to improved greases and high viscosity oilscontaining various metallic salts derived from rosin.

The problemof building up a grease from a lubricating oil or that ofincreasing the viscosity of a lubricating oil is one which has for sometime past been a perplexing one. It came to be known that rosin oils ofvarious grades when added in the form of their metallic salts wouldaccomplish, at least in' part, the desired result. In particular, thefraction of gum rosin oil known as kidney rosin oil" produced bettergreases and oils than did the others. Additional materials which havebeen employed to accomplish the desired end include the metallicresinates of both wood and gum rosin. The use of these materials,however, has not met with great success. 1

As the need develops for lubricating greases and oils of still higherviscosity, it becomes apparent that the capacity of the rosin oil typereagents is not commensurate with that required to produce acceptableproducts. These reagents fail to produce the heavyviscositiesrequired;and furthermore, when incorporated in greases in large amounts, theyimpart a graininess or non-uniformity to the dispersion or solution asthe case may be.

Particularly, with regard to the manufacture of so-called sett" greases,the prior art materials have presented difficulties. In making theseproducts, asmall quantity of rosin oil, for example, is mixed with alubricating oil of light viscosity. Unslaked lime is then stirred in.This is followed by the addition of water. Upon standing, the mixturesets up, forming the "sett component of the grease. A so-called preparedoil is made by dissolving rosin oil in a lubricating oil of higherviscosity than that of the oil need in the sett component. The preparedoil is then mixed with the sett and allowed to stand until the greaseforms. In preparing this typ of grease using the prior art reagents, theresults have been unsatisfactory inasmuch as the products do not possessthe desired smoothness, nor do they have good setting-upcharacteristics.

It is an object of this invention to produce lubricating greases andoils having heavier viscosities or consistencies than those obtainableby prior art methods.

A further object is to produce lubricating greases and oils containing ametal resinate having a metal content higher than that of the metalresinate heretofore used.

It is also an object to produce lubricating greases and oils which aresmooth .in texture and which are not characterized by graininess ornon-uniformity of dispersion or solution as the case may be. I

Other objects of the invention will appear hereinafter.

These objects have been attained by employmg as the bodying agent in thell ase or oil a metallic salt of .a rosin which has been polymerized inaccordance with the various methods therefor. For example, it has beenfound that rosin dissolved in a suitable solvent, such as, benzene, whencontacted with sulfuric acid catalyst, undergoes a metamorphosis. Afterthe catalyst has been removed, the resulting material may be used toproduce metallic salts which in turn may be incorporated in lubricatingoils.

The resulting greases and high viscosity oils have much heavierconsistencies than were formerly obtainable, and they are characterizedby a smoothness and homogeneity which cannot be duplicated by, theproducts of the prior art.

The product in accordance with this invention comprises a solution ordispersion of a metallic salt of a polymerized rosin in a lubricatingoil. Water may be added and emulsified therein to constitute an internalphase. The finished prodnot may also contain relatively small amounts oftalc, graphite, etc. which hereinafter will be called lubricationassistants.

The metallic salts of polymerized 'rosin contemplated by this inventionmaybe produced from the polymerized rosin by heating the polymerizedrosin to an elevated temperature, preferably within the range .of fromabout C. to about 315 C., accomplishing thereby the melting of thepolymerized rosin. The metal is then added, in the form of its acetate,oxide, hy-

droxide, or other reactive compounds, and the heating continued untilthe reaction has pro-v gressed to the desired extent. While it iscontemplated that any metal in the form of an apprporiate reactivecompound may thus be used to produce polymerized rosin salts which mayin turn be used to yield an improved oil. or grease, it has been foundthat metals coming within certain well-defined categories are ofpreferred utility. Thus, it has been I found that the alkali metalscomprising sodium, potassium, etc., and the metals of group II of theperiodic table comprising calcium, zinc, barium, magnesium, etc. are sopreferred. Other metals, particularly de-' sirable but which fit in nowell-defined group, comprise lead, aluminum, tin, and chromium. In themanufacture of the metallic salt of polymerized rosin, it is preferredto use the metal compound hereinbefore described in an amount whichfalls within the range between the amount necessary to produce theneutral salt of the acid constituents of the polymerized rosin and theamount which corresponds to a 100% excess. The metal compound may beused, however, in an amount which falls within the range between thatnecessary to produce neutralization and a 100% excess over thatrequiredfor complete neutralization of the acid constituents of thepolymerized rosin.

The polymerized rosins contemplated to be used in accordance with thisinvention may be those derived from any of the various grades of wood orgum rosin. It is contemplated, too, that the various polymerized rosinacids obtainable from the aforesaid rosins be included as equivalents.These acids comprise abietic, pimaric, sapinic, sylvic, etc. acids, ormixtures thereof. Polymerization may be carried out by various methods,such as, for example, by treatment with various catalysts, as sulfuricacid, boron trifiuoride, stannic chloride, zinc chloride, aluminumchloride, hydrofluoric acid, etc., or by treatment of the rosin with ahigh voltage, high frequency discharge, or by treatment with an acidsludge formed by treatment of rosin with sulfuric acid. Polymerizedrosins prepared by treatment of rosin with sulfuric acid or with an acidsludge formed by treatment of rosin with sulfuric acid, however, arepreferred. The polymerization of rosin by any of these methods isusually carried out with the rosin dissolved'in some suitable organicsolvent, such as, benzene, gasoline, etc. It is desirable in general touse a polymerized rosin which has been obtained from a rosin from whichmost of the color bodies have been removed by a prior treatment.Furthermore, it is contemplated that the polymerized rosin of thepresent invention include those that have, after polymerization, beenfurther refined by means of selective solvents, such as, furfural,phenol, etc. or also by means of adsorbents, such as fullers earth,activated carbon, etc. This refined rosin may be then further refined bya bleach treatment, such as, subjecting the rosin to the action of zincand sodium bisulphate, heat and carbon dioxide, etc.

These polymerized rosins are characterized by having a melting point, asdetermined by the Hercules drop method, above that of ordinary rosin andbelow about 176 C., and an acid number of from about 110 to about 165.It is preferred, however, to use a polymerized rosin having a dropmelting point of from about 90 C. to about 176 C., and an acid number offrom about 120 to about 165. The polymerized rosins having a dropmelting point of from about 135 to about 176 C. are obtained by reducedpressure distillation of products obtained upon treatment of ordinaryrosin with a catalyst, etc. In this way the unpolymerized portion of therosin is either wholly or partially removed.

When rosin is polymerized by means of H2804, an acid sludge is oftenseparated during the processing. By suitable treatment of the sludge,the polymerized rosin constituents in the sludge may be recovered. Thisrecovered polymerized rosin is dark in color, has a drop melting pointof from 120 to 155 C., and has an acid number of from 120 to 145. It maybe used equivalently as all or part of the polymerized rosinhereinbefore mentioned.

In the general preparation of greases and high viscosity lubricatingoils in accordance with this invention, several alternative processesmay be employed. The metallic salts of polymerized rosin may be preparedas hereinbefore described and heated to a temperature ranging fromslightly above their melting points to about 260 C. The desired quantityof lubricating oil may then be added thereto. Alternatively, thelubricating oil and polymerized rosin may be heated at a temperature offrom about C. to about 140 C. until the rosin has dissolved completelyin the oil, and the metal compound added thereto. The total amount ofpolymerized rosin present in the grease in both combined and uncombinedform will be not more than 60% and preferably within the range of fromabout 5% to about 50% based on the weight of the total composition. Anexception to this is presented where an aluminum compound is used in theprocess of making the grease. In that case, the total amount ofpolymerized rosin in the grease will be not greater than about 25%; andpreferably, the total polymerized rosin present will be not greater thanabout 15% based on the total composition.

It will be understood that it is contemplated that the improved greasesof this invention be prepared by employing precipitated" resinatesobtained from polymerized rosin, although this procedure is not thepreferred one. Thus, polymerized rosin may be dissolved in a suitablesolvent and the desired metal compound added thereto. The resultingprecipitated resinates may, after separation from the solvent, beincorporated in lubricating oil to produce the desired grease.

The lubricating greases or oils prepared in accordance with thisinvention may contain water emulsified therein to the extent of fromabout 1% to about 10% based on the total composition. Lubricatingassistants such as graphite, powdered mica, etc. may be added to theextent of from about 0.5% to about 25%. Both the water and thelubrication assistant may be added during the processes hereinbeforedescribed or thereafter. a

In the particular instance where a sett oil is prepared in accordancewith this invention, polymerized rosin is dissolved in'a quantity oflubricating oil by any suitable means. Desirably, this may beaccomplished by heating the mixture at a temperature of from about C. toabout C. After solution has taken place, a suitable metal compound, ashereinbefore described, is added and the whole agitated. Thisconstitutes the sett. A "prepared oil is made by dissolving polymerizedrosin in another quantity of lubricating oil. This prepared oil is thenadmixed with the sett. time the mixture sets up forming a grease.

It will be understood that any lubricating oil may be used in producingthe improved products of this invention. Although oils having particularviscosities are used in the specific examples,

it is intended that the broad concept herein disclosed be in no waylimited thereby. Actually, the particular oil chosen in any case willdepend upon the final disposition of the grease or oil produced.

The following specific examples are given as illustrative of particularembodiments of the invention. The polymerized rosin employed in the Uponstanding for a first four examples was produced from rosin by treatmentwith sulfuric acid catalyst and had a melting point by the Hercules dropmethod of 100 C. It was thereafter refined by subjection to heattreatment in presence of carbon dioxide. All parts and percentagesthroughoutthe specification and claims attached are by weight unlessotherwise stated.

The lubricating oil (A), having a viscosity at 100 F. of 100 seconds ina Universal Saybolt viscosimeter, and the 25-part portion of polymerizedrosin were heated and agitated at 93 C. until solution was efiected,after which the lime was slowly stirred in. A light brown "settresulted. Then, the lubricating oil. (B), having a viscosity at 212 F.of 235 seconds in a Universal Saybolt visc-osimeter, and the 200-partportion of polymerized rosin were heated at 93 C. with agitation I untilsolution was efiected. This constituted the oil. Holding the temperatureof this prepared" oil at between 53 C. and 65 C., it was stirred intothe sett." A standard sett grease was prepared using equivalentquantities of unpo-lymerized rosin. Upon comparison, the greasecontaining polymerized rosin was much smoother and had a decidedlyheavier consistency.

"prepared EXAMPLE 2.

. Parts Polymerized rosin 39.45 Zinc oxide .55, Lubricating oil 60.00

The polymerized rosin was melted and the temperature run to a maximum of232 C. At this maximum temperature the zinc oxide was slowly added.After the zinc oxide had completely reacted, the temperature was allowedto fall to 215 C., at which point the lubricating oil was added. Thisparticular oil had a viscosity at 100 F. of 100 seconds in a UniversalSaybolt viscosimeter. A smooth viscous grease resulted. A standard madeby the same process with the exception that WG wood rosin wassubstituted for the polymerized rosin was grainy, less viscous and ofdefinitely darker color.

ExAMPLn 3 Parts Polymerized rosin 39.15 Litharge 0.85 Lubricating oil60.00

The polymerized rosin was melted and the temperature increased to 232 C.At this temperature the litharge was added and the temperature slowlyraised to 274 C. After complete reaction had taken place with thelitharge, the temperature was allowed to fall to 260 C. At thistemperature the oil, having the same characteristics as that used inExample 2, was slowly stirred in. A smooth, more viscous grease thanthat produced in a similar manner with the use of unpolymerized rosinresulted.

i EXAMPLE 4 l Parts Polymerized rosin ....L-.'. 10

Aluminum propoxide (employed in the form of a 37% solution in propylalcohol) 2.07 Lubricating oil The lubricating oil, havingthe samecharacteristics as that of Example 2, and polymerized rosin were heatedwith agitation at 93 C. until solution was eifected. The temperature wasthen allowedto rise above 107 C. After complete solution had beeneifected, the temperature was allowed to fall to 82 C., at whichtemperature the aluminum propoxide solutionwas stirred in. Uponstanding, a grease having better color and definitely improved viscositycharacteristics, when compared with a standard made using un-,polymerized rosin, resulted.

EXAMPLE 5 Sett 1 Parts Polymerized rosin 10 Lubricating oil (A) 30Calcium oxide u 3.5 Water -1 15 Prepared oil Parts Polymerized rosin 30Lubricating 011' (B) 50 The polymerized rosin .used in this example wasone obtained from anacid sludge which.

resulted from the treatment ofv unploymerized rosin with sulfuric acid.The lubricating -oil (A), having a viscosity at F. of 100s'econds in aUniversal Saybolt viscosimeter, and

the 10-part portion of polymerized rosin were heated with agitation toC. When the polymerized rosin had completely dissolved, the solution wascooled to 90 C. and the calcium oxide was stirred in. The water was thenadded accompanied by vigorous agitation. "The resulting materialconstituted the sett." "The'lubrieating oil (B), having a viscosity at100 F.'of 500 seconds in a Universal Saybolt viscosimeter, and the30-part portion of polymerized rosin were heated at C. and held thereuntil solution was effected. This solution constituted the prepared oil.Holding the temperature of this prepared oil at between 53 C. and 65 C.,it was stirred into the sett. A grease having a very smooth texture andheavy body set upon standing.

By the use of the metal salts of polymerized rosin in accordance withthe instant invention, it is possible to produce lubricating greases andhigh viscosity lubricating oils in which there is no graininess ornon-unformity of solution or dispersion. In addition, these improvedgreases have better color than those of the prior art. Another advantageobserved is the production of lubricating greases and oils which havemuch higher viscosities than those previously obtainable by prior artmethods. A'still further advantage offered by the use of metal salts oipolymerized rosin in the production of greases and high viscosity oilsis found in their yielding compositions containing greater quantities ofmetal in the form of the resinate than have heretofore beenpossibleusing identical proportions of rosin. Increased viscosities and bettersetting-up properties result therefrom.

It will be understood that the details and examples hereinbefore setforth are illustrative only and that the invention as broadly describedand claimed is in no way limited thereby.

What I claim and desire to protect by Letters Patent is:

- 1. A lubricant, comprising a lubricating oil and a metal salt ofpolymerized rosin in sui'iicient quantity to substantially thicken theoil.

2. A lubricant comprising a lubricating oil and a metal salt ofpolymerized rosin wherein the metal is selected from group 2 of theperiodic table, said salt of polymerized rosin being present insuflicient quantity the oil.

3. A lubricant comprising a lubricating oil and an alkaline earth metalsalt of polymerized rosin in sumcient quantity to substantially thickenthe oil.

4. A lubricant comprising a lubricating oil and a calcium salt orpolymerized rosin in sumcient quantity to substantially thicken the oil.

5. A lubricant comprising a lubricating oil and an alkali metal salt ofpolymerized rosin in sufflcient quantity to substantially thicken theoil.

6. A lubricant comprising a lubricating oil and a sodium salt ofpolymerized rosin in suflicient quantity to substantially thicken theoil.

7. A lubricant comprising a lubricating oil and a lead salt ofpolymerized rosin in suflicient quantity to substantially thicken theoil.

8. A lubricant comprising a lubricating oil, a metal salt of polymerizedrosin, and containing water emulsified therein, said salt of polymerizedrosin being present in sufilcient quantity to substantially thicken theoil.

9. A lubricant comprising a lubricating oil, a metal salt of polymerizedrosin, a lubrication assistant, and containing water emulsified therein,said salt of polymerized rosin being present in suflicient quantity tosubstantially thicken the oil. I

10. Alubricant comprising a lubricating oil, a metal salt of polymerizedrosin, powdered graphite, and containing water emulsified therein, saidsalt of polymerized rosin being present to substantially thicken insumcient the oil.

v 11. A lubricant comprising a lubricating oil and a calcium salt 01'polymerized rosin, the total polymerized rosin present in both thecombined and uncombined i'orms being not greater than about 60% byweight based on the finished product and said salt or polymerized rosinbeing present in sufllcient quantity to substantially thicken the oil.

12. A lubricant comprising a lubricating oil and a sodium salt ofpolymerized rosin, the total polymerized rosin present both in thecombined and uncombined forms being not greater than about 60% by weightbased on the finished product and said salt of polymerized rosin beingpresent in sufilcient quantity to substantially thicken the oil.

13. A lubricant comprising a lubricating oil and a lead salt ofpolymerized rosin, the total polymerized rosin present in both thecombined and uncombined forms being not greater than about 60% by weightbased on the finished product and said salt of polymerized rosin beingpresent in suflicient quantity to substantially thicken the oil.

14. A lubricant comprising a lubricating oil and a calcium salt ofpolymerized rosin, the total polymerized rosinjpresent in both thecombined and uncombined forms being within the range of from about 5% toabout 50% by weight based on the finished product.

15. A lubricant comprising a lubricating oil and a sodium salt ofpolymerized rosin, the total polymerized rosin present both in thecombined and uncombined forms being within the range of from about 5% toabout 50% by weight based on the finished product.

16. A lubricant comprising a lubricating oil and a lead salt ofpolymerized rosin, the total polymerized rosin present both in thecombined and uncombined forms being 'within the range of from about 5%to about 50% by weight based on the finished product.

IRVIN W. HUMPHREY.

quantity to substantially thicken

